Trickey A, et al. - This study aimed at determining whether CD4:CD8 ratio and CD8 count were prognostic for all-cause, AIDS, and non-AIDS mortality in virologically suppressed patients with high CD4 count. In this large cohort collaboration, there appeared very small correlation of the magnitude of adjusted associations of CD4:CD8 ratio or CD8 count with mortality for them to be useful as independent prognostic markers in virally suppressed patients on ART.

Methods

• This study utilized data from 13 European and North American cohorts of human immunodeficiency virus–infected, antiretroviral therapy (ART)-naive adults who started ART during 1996–2010, who were followed from the date they had CD4 count ≥350 cells/μL and were virologically suppressed (baseline).
• Stratified Cox models were used for determining unadjusted and adjusted (for sex, people who inject drugs, ART initiation year, and baseline age, CD4 count, AIDS, duration of ART) all-cause and cause-specific mortality hazard ratios for tertiles of CD4:CD8 ratio (0–0.40, 0.41–0.64 [reference], > 0.64) and CD8 count (0-760, 761-1138 [reference], >1138 cells/μL) and examined the shape of associations using cubic splines.

Results

• 1834 of 49865 patients died during 276526 person-years (249 AIDS-related; 1076 non-AIDS-defining; 509 unknown/unclassifiable deaths).
• Data revealed little evidence suggesting CD4:CD8 ratio as prognostic for all-cause mortality after adjustment for other factors: the adjusted hazard ratio (aHR) for lower vs middle tertile was 1.11 (95% confidence interval [CI], 1.00-1.25).
• CD8 count indicated U-shaped association with all-cause mortality: aHR for higher vs middle tertile was 1.13 (95% CI, 1.01–1.26).
• Decline in AIDS-related mortality was observed with increasing CD4:CD8 ratio and decreasing CD8 count.
• Little evidence was gained suggesting CD4:CD8 ratio or CD8 count as prognostic for non-AIDS mortality